Failure Load and Pattern Prediction for the Proximal Femur using Linear FiniteElement Method

Quantitative computational tomography (QCT) basedfinite element analysis (FEA) is an emerging method forbone strength estimation and investigation of mechanicalbehavior of bone structure. The objective of this study isto develop a fast and accurate procedure to predict thevalue of failure load and fracture site of femoral bone invarious loading orientations. Respectively, ten freshfrozen proximal femurs were CT-scanned andsubsequently, the specimens fractured in eight loadingconditions relevant stance and orientations other thanstance. Besides, Load-displacement curves wereacquired to define the failure load and the experimentswere carried on until crack become visible on thesurface of the femur. In consequence, ۳D finite elementmodels of these specimens were provided, and linearanalysis was performed to use. two courses of actionbased on strain energy density risk factor (RF) andequivalent strain risk factor (ESRF) was evaluated topredict failure load and patterns. The procedure wasapplied sorting of all elements in dataset by value of RFand ESRF and calculations of critical elements thatappear at the top of dataset. As a consequence ofempirical tests, very good correlation was seen betweenpredicted load and experimental results (RF procedure:slope = ۰.۹۱۲, R۲ = ۰.۸۴۲ and ESRF procedure: slope =۰.۸۴۶, R۲=۰.۸۰۳). Moreover, the proposed equivalentstrain and strain energy density managed appropriatelyto discriminate the level of failure risk, the location andpattern of failure onset in all the modeled specimens incomparison with experiments. Present study can help tocause the development of a diagnostic method that candetect osteoporotic fracture for aged patients.

کلیدواژه ها:

bone ، finite elements analysis ، fracturepatterns ، quantitative computed tomography ، strain energydensity